Railway signaling.



L. V. LEWIS.

v RAILWAY SIGNALING.

APPLICATION FILED JULY 25. 1911. 1 ,96,95, Patented Mar. 4,1919.

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LLOYD V. LEWIS, OF EDGEWOOD BOROUGH, SWITCH & SIGNAL COMPANY, OF SWISSPENNSYLVANIA, ASSIGNOR TO THE UNION VALE, PENNSYLVANIA, A CORPORATION OFRAILWAY SIGNALING.

Specification of Letters Patent.

Patented Mar. at, 1919.

Application filed July 25, 1917. Serial No. 182,651.

To all whom it may concern:

Be it known that I, LLoYn V. LEWIS, a citizen of the United States,residing at Edgewood borough, in the county of Allegheny. and State ofPennsylvania, have invented certain new and useful Improvements inRailway Signaling, of which the following is .a specification.

My invention relates to railway signaling, and particularly to signalingof the type comprising alternating current track circuits.

I will describe one form of signaling system embodying my invention, andwill then point out the novel features thereof in claims.

In the accompanying drawings, Figure l is a View. showingdiagrammatically one form of signaling system embodying my invention,and Fig. 2 is a View similar to Fig. l but showing a modificationthereof also embodying my invention. I

Similar reference characters refer to similar parts in each of theviews.

Referring first to Fig. 1, the reference characters 2, 2 designate thetrack rails of a railway over which trafiic normally moves in thedirection indicated by the arrow. The rails are divided, by means ofinsulated joints 3, into a plurality of successive track sections A-B,B-C, CD, etc. Each track section is provided with a track circuitcomprising the track rails themselves, means for supplying alternatingsignaling current of one frequency or another thereto,

and two relays H and H.

Each relay H and H, in the form here shown, is of the polyphase motortype, comprising two stator windings 4c and 5, and a rotor 6 whichactuates the contact fingers. The winding 4, which I will term the trackwinding, is connected directly with the track rails of the correspondingsection, while the other winding 5, which I will termthe local winding,is supplied with alternating current independently of the track rails,the frequency of the current thus supplied to winding 5 being the sameas one or the other of the frequencies supplied to the rails. I willassume herein that the two frequencies are 90 and 60 cyclesrespectively, although I do not wish to limit myself to currents of anyspecific frequencies.

For each track section I provide two transformers U and U, the primariesof which are connected to generators K and K respectively, through themedium of transmission mains M. The generators K and K deliver 90 and 60cycle current respectively, hence the frequency delivered by eachtransformer is indicated by the exponent applied to the referencecharacter U for such transformer. One terminal of the secondary oftransformer U for each section is connected with one terminal of thesecondary of transformer U for the same section, and a common wire 0 isconnected with the junction of these two terminals.

The two relays for each section control the supply of current to therails of the section in the rear, this control being such that when bothrelays are deenergized current of one frequency is supplied to thesection in the rear, while current of the other frequency is supplied tosaid section when either one or the other of the relays is energized. Asshown in Fig. 1, this control is effected through the medium of aslowrelease relay ll which is controlled by relays H and H in such.manner that relay \V is deenergized when both relays H and H aredeenergized, and that relay W is energized when either relay H or H isenergized. The circuit for relay IV when relay H is energized (seesection A-B) is from the secondary of transformer U through wires 60 and7, contact 11 of relay H, wires 12 and 10, relay and common wire 0 totransformer U \Vhen relay H is energized, the circuit for relay W issimilar (see section BC) except that it includes wire 8 and contact 9 ofrelay H. When relay IV of any one section is de'e'nergized, 60 cyclecurrent is delivered to-the rails of the section in the rear, thecircuit being (see sec tion C-D) from the secondary of transformer Uthrough wire (30, back point of contact 13 of relay \V, wire ll, primaryof a transformer I, and common wire 0 to transformer ll. Thesecondary oftransformer P is connected across the rails of the section in the rear.When relay V is energized, 90 cycle current is supplied to the rails ofthe section in the rear from secondary of transformer U through wire 90,front point of contact 13 of relay V, thence as before.

The local winding 5 of each track relay H and H is supplied with currentof the frequency to whlch the relay is to respond, this supply beingcontrolled by a back contactof the other relay H or H of the samesection. This winding 5 of each relay H, which is the 90 cycle relay, isat times supplied with 90 cycle current through a circuit from thesecondary of the adjacent transformer U through wire 90, back point ofcontact 15 of relay H, wire 16, winding 5, wires 17 and O to transformerU Similarly, winding 5 of the 60 cycle relay H is at times supplied with60 cycle current through a circuit-from the secondary of the adjacenttransformer U through wires 60vand 7, back point of contact 18 of relayH, wires 19 and 20, windin 5, and common wire 0 to transformer U It willbe seen, therefore, that when either relayH or H of a given tracksection is energized, the local winding of the other relay isdenergized, so that there is no tendency for such other relay to chatteras would be the case if its two windings were supplied with currents ofdifferent frequencies.

For each track section I provide a signal S, which is adapted toindicate stop, caution. and proceed. Each of these signals is controlledby the relays H and H for the corresponding section in such manner thatthe signal indicates stop when both relays are denergized, caution whenrelay H is energized and H is denergized, and proceed when relay H isenergized and H is deencrgized. As here shown, each signal comprisesthree electric lamps R, Y and G, indicating when illuminated stop,ca-ution and proceed, respectively. For reasons which will be pointedout hereinafter these lamps are in part controlled by contact 21 ofrelay W for the corresponding track section.

When both relays H and H (see section C-D) are denergized, relay W forsuch section is deenergized, and the circuit for the stop lamp R of thesignal for such section is then from secondary of transformer U throughwires 60 and 7 back point of coni tact 18' of relay H, Wire-19, backpoint of contact 21 of relay WV, lamp R and common wire 0 to transformerU. This signal then indicates stop. \Vhen relay H is energized (seesection BC) relay W is also energized, and the cautionlamp Y is illuminated, the circuit being from the secondary of transformer U throughwires 60 and 7, back point of contact 18, wire 19, front point ofcontact 21 of relay W, lamp Y, and common Wire 0 to transformer U \Vhenrelay H is energized (see section A-B), the circuit for the proceed lampG is from transformer'U? through wires 60 and 7, front point of contact18 of relay H, wire 22, lamp G, common wire 0 to transformer U In thedrawing I have shown a car or train in track section C-D so that bothrelays H and H for this section are deenergized and When train T passesout of section C-D,

into the next section in adyance the rails of section CD will besupplied with 60 cycle current so that relay H will become energized andrelay W will consequently pick up, thus causing the signal for thissection to change from stop to caution. The current supplied to therails of section BC will then be changed from 60 to 90 cycles, so thatrelay H for this section will become de'e'nergized and relay H willbecome energized. During this change of frequency there will be aninstant during which both relays H and H are deenergized; that is,during which the front contacts of both of these relays will be open.During this instant relay. W will be de-' energized, but owing to thefact that this is a slow-release relay its front contacts will not beopened. Consequently, during this instant contact 21 will not fall toits back point to illuminate lamp R, and there will 'BC, contactl?) ofrelay W for this section will not change its position; and consequentlythe rails of section A-B will continue to be supplied with 90 cyclecurrent during the interval in which both relays H and H of section B-Care de'e'nergized.

The system shown in Fig. 1 provides for protection in case ofbroken'down insulated rail joints. This is accomplished by connectingthe secondaries of transformers P with the rails of the track sectionsin such manner that at any given instant the currents supplied toadjacent track sections, if of the same frequency, are 180 out of phase.Then if the insulated joints 3 between any two track sections shouldbreak down, the current reaching the relays of the forward section fromthe rails of the rear section would be in such direction that the relay,whose local element is energized at the same frequency, would bereversely energized, and, consequently, would be operated in such manneras to open it front contacts and close its back contacts. For instance,if the joints 3 at location A should break down cates proceedf, '90cycle current would be supplied to winding 4 of relay H from transformerP of the section in the rear of location A, and this-90 cycle currentwould be stronger than that received from transformer P of section ABbecause the former transformer is much closer to the relay than is thelatter. Relay H at location A would, consequently, be positivelyoperated to the open position, and inasmuch as relay H is already open,the signal S for section AB would change to stop indication. Assume nowthat while section C-D is occupied by'the train T the joints 3 atsection C should break down. 60 cycle current would then be supplied tothe windings 4 of'relays H and H at location C. This current would, ofcourse, not coact with the 90 cycle current in winding 5 of relay H, andconsequently this relay would continue to be denergized. The 60 cyclecurrent would, however, coact with 60 cycle current in winding of relayH to positively hold this relay in the open position. The signal S forsection C-D would, consequently, continue to indicate stop. With thiscondition, if the train passes out of section CD so that 60 cyclecurrent is supplied to the rails of section CD at the exit end thereof,relays Hand H would remain open because the voltage reaching relay Hfrom except that the circuits section BC would overbalance that reachingthis relay from the exit end of section C'D. Signal S for section CDwould consequently continue to indicate stop.

Referring now'to Fig. 2, the system here shown is slmilar to that shownare so arranged that both relays H and H are energized when a proceedsignal is to be given, and the slow release relays are omitted.

With the arrangement shown in Fig. 2, when both relays H and H aredenergized- (see section -C D), 60 cycle current is fed to the localWinding 5' of relay H, and 90 cycle current is fed to the local winding5 of relay\H, as is the case in Fig. 1. The circuit for this winding 5of relay H is then from the secondary of transformer U" through wires 60and 7, back point of contact 23 of relay H, wire24, winding 5, wire 0 totransformer U At the same time, the circuit for winding 5 of relay H isfrom secondary of transformer U through wires-90 and 25, back point ofcontact 15 of relay H, wires 26 and 27, winding 5, and common wire 0 totransformer U If now, with relays H and H denergized, 6O cycle currentis fed'to the track rails (see section BC), relay. H will become ener=gized because both of its windings are supplied with 60 cycle current."Relay H will not be energized. buton the other hand the in Fig. 1

hen e relay H will not chatter. Thus far the system is in substance thesame as that shown in Fig. 1.

Assume now that with H energized and H denergized (see section BC), thecurrent in the rails is shifted from 60 to 90 cycles. Relay H will dropbecause of the different frequencies in its windings, whereupon contact15 will supply 90 cycle current to winding 5 of relay H so that thisrelay will pick up. In so doing, however, this re lay supplies its ownwinding'5 with 90 cycle current independently of contact 15 of relay H,the circuit being from secondary of transformer U" through wires 90 and25, contact 28 of relay H, wires 29 and 27, winding 5, common wire 0 totransformer U Hence the subsequent energization of relay H by meansabout to be explained does not deenergize H. The closing of relay Hcloses a circuit supplying 90 cycle current to winding 5 of relay H, thecircuit being from secondary of transformerU" through wires 90, 25' and30, front point of contact 23 of relay H, wire 24, winding 5, commonwire 0 to transformer U With 90 cycle current in the rails, then, bothrelays H and H are energized, because windings 5.of both of these relaysare also supplied with 90 cycle current (see section The supply ofcurrent to the rails of each section is governed by relay H of thesection in advance. This current is '90 or 60 cycles according as therelay is energized or deenergized, and the control is effected by formerU. -When relay H is energized and relay H is denerg'ized the cautionlamp Y is illuminated (see section B-C) the circuit being the same asthe circuit for lamp R up to and including wire 33, then through frontpoint of contact 34 of relay H, wire 36, lamp Y, and common wire 0 totransformer U When both relays H and H are energized, the proceed lamp Gis illuminated (see section A-B). the circuit beingfrom transformer Uthrough wires 60 and 7, front point of contact 32 of relay H, frontpoint of contact 37 of relay H, wire 38, lamp G, and common wire 0 totransformer U The operation of the apparatus is as follows:

Section CD being occupied by a car or is energized and relay H isdenergized.

Consequently, signal S for section B-C indicates caution. Ninety cyclecurrent is supplied to the rails of section AB so that both relays forthe latter section are energized and the signal S for the latter sectionindicates proceed.

When the car or train T passes out of section C-D into the next sectionin advance,

relay H for section G-D will become energized thereby causing thecaution lamp Y of this section to become illuminated. 90 cycle currentwill then be supplied to the rails of section B-C, whereupon relay H forthis section will become energized, thus supplying 90 cycle current toits winding 5 and also to the winding 5 of relay H so that both relaysfor section B-C are energized. The proceed lamp G of this section BGthen becomes illuminated.

Although I have herein shown and described only two forms of signalingsystems embodying myinvention, it is understood that various changes andmodifications may be made therein within the scope of the appendedclaims without departing from the spirit and scope of my invention.

Having thus described my invention, what.

I claim is:

1. A railway signaling system comprising a plurality of track sections,two relays for each section receiving energy from the rails I of thesection and responsive respectively to alternating currents of twodifferent frequencies, means controlled-by the relays of each sectionfor supplying current of one of said frequencies or the other to therails of the section in the rear, and signals controlled by said relays.

2. A railway signaling system comprising a plurality of track sections,two relays for each section receiving energy from'the rails of thesection and responsive respectively to alternating currents 'of twodifferent frequencies, means controlled by the relays of each sectionfor supplying current of one of said frequencies to the rails of thesection in the rear when both relays are .deenergized and for supplyingcurrent of the other frequency to the rails of the section in the rearwhen either relay is energized, and signals controlled by said relays.

3. A railway signaling system comprising a plurality of track sections,two relays ,for

each section each comprising a track wind ing and a local winding, eachtrack winding receiving energy from the track rails of the correspondingsection, means for supplying alternating current of one frequency oranother to the rails of each section, means for supplying the localwindings of the relays for each section with currents of said twofrequencies respectively, the supply of curtrolled by said relays.

4. A railway signaling system comprising a plurality of track sections,two relays for each section each comprising a track winding and a localwinding, each track winding receiving energy from the track rails of thecorresponding section, means for supplying alternating current of onefrequency or another to' the rails of each section, means for supplyingthe local windings of the relays for each section with currents of saidtwo frequencies respectively, and signals for the sections controlled bysaid relays.

5. A railway signaling system comprising a plurality of track sections,two relays for each section receiving energy from the rails of thesectionand responsive respectively to alternating currents of twodifierent frequencies means controlled by the relays of each sectionforsupplying current of one of said frequencies or the other to therails of the section in the rear; and a signal for each sectioncontrolled bythe relays for the section and indicating stop when bothrelays are deenergized, caution. when one relay is energized, andproceed when the other relay is energized.

6. A railway signaling system comprising 7 a plurality of tracksections, two track relays for each section receiving energy from thethe track-relays for the section and energized when either track relayis energized, means controlled by the slow release relay for eachsection for supplying current of one of said frequencies or the other tothe rails of the section in the rear, and signals controlled by saidtrack relays and slow release relays.

7 A railway signaling system comprising a plurality of track sections,two relays for each section each comprising a track winding and a localwinding, each track winding receiving energy from the rails of thecorresponding section, means for supplying the local winding of onerelay for each section with alternating current of one frequency, andthe local winding of the other relay for each section with alternatingcurrent of anotherfrequency, means controlled by a relay of each sectionfor supplying alternating current of one of said frequencies or theother to the rails of the section in the rear, and signals for thesections controlled by said relays.

8. A railway signaling system comprising a plurality of track sections,two relays for each section each Comprising a track windnating currentof either of said frequencies 10 ing and a local winding, each trackwinding to the rails of each section, and signals for receiving energyfrom the rails of the correthe sections controlled by said relays.

sponding section, means for supplying the V In testimony whereof I affixmy signature local winding of one relay for each section in presence oftwo witnesses.

with alternating current of one frequen y, v LLOYD V. LEWIS. and thelocal winding of the other relay for Witnesses: each section withalternating current of an- A. HERMAN WEGNER,

other frequency, means for supplying alter-- E. P. CRUM.

